M 109

M109 (Messier 109) is a barred spiral galaxy located in the constellation Ursa Major, approximately 55 million light-years from Earth. Its characteristic structure includes a central bar with two bright spiral arms extending from the base of the bar. The galaxy is classified as a SBbc (barred spiral galaxy).

The galaxy has an angular size of 7.3 by 4.5 arcminutes and is approximately 120,000 light-years in diameter. Its structure includes active star-forming regions in its arms, as well as numerous star clusters and nebulae.

M109 was discovered by Pierre Méchain in 1781 and later added to the Charles Messier catalog. It is the most distant object in the Messier catalog, followed by M91. The central region of the galaxy contains a faint inner ring structure around the bar. Observations show that the gas distribution inside the galaxy is affected by the bar, creating a empty space in the center (H I-absence).

This galaxy is part of the Ursa Major Group of galaxies, which includes about 50 galaxies. M109 also has several satellites, such as UGC 6923, UGC 6940, and UGC 6969, which are irregular galaxies. In 1956, a supernova SN 1956A (type Ia) with a maximum magnitude of 12.3 was observed.

The galaxy is difficult to observe due to its dimness and blurriness, but it is easily visible in the spring, using the bright star Fehda in Ursa Major as a marker to find it. Under dark skies, M109 can be seen as a band of light, but a more powerful telescope will be needed to study it in more detail, as it will show the core region of the galaxy surrounded by the blurry light.

Images of the galaxy obtained with the Hubble Space Telescope allow us to study the bright core of this spiral galaxy, which helps to study supermassive black holes in various galaxies.